This invention relates to a method for metal plating, particularly, a method for selective plating from electroless plating solutions.
While it is possible to produce high resolution patterns by electroless deposition techniques wherein masking is employed to delineate the pattern, such plating processes require multiple steps. It is necessary to employ a photoresist to mask the surface, to selectively expose the photoresist mask, to plate the surface, and finally, to strip the mask. This process is a multistep process.
It is known to expose a substrate immersed in an electroless plating solution to a high intensity light source to enhance the plating rate. While this technique increases the plating rate, it is not well suited for preferentially plating patterns since there will be a mixing of the activated solution with the nonactivated solution, thus reducing the resolution of any plated pattern.
It is also known to coat a surface to be plated with a sensitizing solution. The coated surface is exposed to light to form a catalytic layer capable of catalyzing the deposition of metal thereon from an electroless metal deposition solution.
We have discovered a novel method for selective maskless electroless plating.
Accordingly, it is an object of the present invention to provide a novel method for selective maskless electroless plating.
Other objects and advantages of the present invention will be apparent to those skilled in the art from a reading of the following description of the invention.